Executable flagging patch

[Gustavo Niemeyer]

> > Doing something similar in MergeTree.readonly_path would be nice
> > indeed.
> 
> Actually, MergeTree.readonly_path should be killed, because it's
> expensive and all of the information we want can be gotten with other
> Tree methods.

It's your code, so you certainly know if it's wrong or not
much better than I do. Even then, what was said is valid
for the current code, or for whatever you introduce next.

-- 
Gustavo Niemeyer
http://niemeyer.net